1. Field of the Invention
The present invention generally relates to a sheet feeding device that has a sheet feeding path. In particular, the invention relates to mechanisms for opening sheet feeding paths in a sheet feeding device.
2. Description of the Related Art
A known image recording apparatus, e.g., a printer, a copier, and the like, is provided with a sheet feeding device that feeds a plurality of sheets of recording medium, e.g., paper. The plurality of recording mediums are set in a sheet-feeding cassette and fed to a recording position at which an image is recorded on each of the recording medium. An example of such an image recording apparatus is described in Japanese Unexamined Patent Application Publication No. 2006-64727.
The known image forming apparatus, e.g., the one described in Japanese Unexamined Patent Application Publication No. 2006-64727, has a two-sided unit mounted thereon. The two-sided unit has a switchback carrying path and a paper re-feeding path. The two-sided unit is disposed on the main body of the image forming apparatus. The two-sided unit can be turned in a unit-opening direction. A paper-carrying path is formed at a space between the main body of the image forming apparatus and the two-sided unit. A sub-rotating unit is disposed at the inner-surface side of the two-sided unit. The sub-rotating unit can rotate. The paper re-feeding path is formed between the two-sided unit and the sub-rotating unit. The sub-rotating unit is urged to open the paper re-feeding path. When the two-sided unit opens the paper-carrying path, the sub-rotating unit simultaneously opens the paper re-feeding path. Thus, it is possible for a user to remove a jammed sheet of recording paper from either the paper-carrying path or the paper re-feeding path.
Nevertheless, the mechanism described in the known sheet feeding apparatus can not be adopted in a sheet feeding device with a dual path configuration. A dual path configuration has a first sheet feeding path and a second sheet feeding path with a sheet-guiding member disposed therebetween. The first sheet feeding path and the second sheet feeding path do not simultaneously feed sheets of recording mediums. In order to open both of the first sheet feeding path and the second sheet feeding path, it is necessary to detach the sheet-guiding member from the first sheet feeding path and the second sheet feeding path. If both of the first sheet feeding path and the second sheet feeding path are opened when a sheet of recording medium is jammed in the second sheet feeding path, the sheet-guiding member collides with the sheet of recording medium that is jammed in the second sheet feeding path, and thereby causes damage to the jammed sheet of recording medium.
Moreover, when no recording paper is present in the second sheet feeding path, it is preferable to open the first sheet feeding path and the second sheet feeding path at the same time. However, in a sheet feeding device with each of the first sheet feeding path and the second sheet feeding path opened independently, it is practically impossible to remove a sheet of recording paper that is jammed on the inner first sheet feeding path unless a user opens both the outer second sheet feeding path and the inner first sheet feeding path. If a user is not aware of the existence of a plurality of paper feeding paths, the user may have difficulty finding the paper which is jammed on the inner first paper feeding path even though the user has opened the outer second paper feeding path. Without removing the jammed paper, the attempt to restart paper feeding results in a failure because the sheet of recording paper remains jammed in the first paper feeding path.